Kathy Schroeder: The Great Hammerhead / Setting the Longline, September 24, 2019

NOAA Teacher at Sea

Kathy Schroeder

Aboard NOAA Ship Oregon II

September 15-October 2, 2019


Mission: Shark/Red Snapper Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: September 24, 2019

Weather Data from the Bridge

Latitude: 29.15258
Longitude: 93.02012
Temperature: 87°F
Wind Speeds: E 10 mph


Science and Technology Log

My last blog left off with a late night longline going in the water around 9:00pm on 9/23/19.  We were able to successfully tag a great hammerhead, a scalloped hammerhead, and a tiger shark.  We also caught a blacknose shark, three gafftopsail catfish (Bagre marinus), and three red snappers. 

female great hammerhead
Female great hammerhead caught on 9/23/19 aboard NOAA Ship Oregon II
male scalloped hammerhead
Male scalloped hammerhead caught on 9/23/19 aboard NOAA Ship Oregon II


Deploying the Longline

Today I’m going to explain to you the five jobs that we rotate through when we are deploying the longline.  When there are about 15-20 minutes before deployment we grab our sunglasses, personal floatation device (pfd) and rubber boats and head to the stern of the ship.  All scientists are responsible for helping to cut and bait all 100 gangions (hooks and line).  The hooks are 15/0mm circle hooks and the gangion length is 3.7m long.  The bait used for this is Atlantic mackerel cut into chunks to fit the hooks.  We are all responsible for cleaning the deck and the table and cutting boards that were used. 

baiting hooks
Kristin cutting bait and Taniya and Ryan baiting the 100 hooks

The first job on the deployment is setting up the laptop computer.  The scientist on computer is responsible for entering information when the high flyer, the three weights (entered after first high flyer, after gangion 50 and before final high flyer), and the 100 baited gangions entered into the water.  This gives the time and the latitude and longitude of each to keep track of for comparison data. 

The second job is the person actually putting the high flyer and buoy in the water.  Once the ship is in position and we receive the ok from the bridge it is released into the water.  The high flyer is 14ft from the weight at the bottom to the flashing light at the top. (see picture) 

high flyer
Kristin and Kathy getting ready to put the first high flyer in the water

The third job is the “slinger”.  The slinger takes each hook, one by one, off of the barrel, lowers the baited hook into the water,  and then holds the end clamp so that the fourth scientist can put a tag number on each one (1-100).  It is then handed to the deckhand who clamps it onto the mainline where it is lowered into the water off the stern. 

numbers on gangion
Placing the numbers on the gangion before being put on the mainline

The final job is the barrel cleaner.  Once all the lines are in the water the barrel cleaner takes a large brush with soap and scrubs down the inside and outside of the barrel.  The barrels are then taken to the well deck to get ready for the haul in.  The last weight and high flyer are put into the water to complete the longline set, which will remain in the water for one hour.  Everyone now helps out cleaning the stern deck and bringing any supplies to the dry lab.  At this time the CTD unit is put in the water (this will be described at a later time).   


Personal Log

Last night was so exciting, catching the three large sharks.  During this station I was responsible for the data so I was able to take a few pictures once I recorded the precaudal, fork, and total length measurements as well as take a very small fin sample and place it in a vial, and record the tagging numbers. 

Shout Out:    Today’s shout out goes to my wonderful 161 students, all my former students, fellow teachers, especially those in my hallway, my guest teachers and all the staff and administration at Palmetto Ridge High School.  I would also like to thank Mr. Bremseth and Michelle Joyce for my letters of recommendations! 

I couldn’t have been able to do this without all of your help and support.  I have sooo much to tell you about when I get back.  Go Bears!!

21 Replies to “Kathy Schroeder: The Great Hammerhead / Setting the Longline, September 24, 2019”

    1. What’s the significance of taking a fin sample from each shark you tag? What are you tracking when doing so?

  1. How long did it take the whole team aboard the boat to bait and number all of the hooks on the longline?

  2. How would you describe this experience to a fellow marine biologist and did this research expedition strengthen your views on the way us humans treat our oceans in terms of waste?

  3. Its seems like such a cool opportunity to spend your time researching interesting animals, though I’m sure the weather did not help you complete all your tasks

  4. I’m glad you got to experience this a second time, and I hope you had a lot fun, especially being an alumni!

  5. Does taking the fun samples hurt the fish in any way, not only pain wise but swimming ability? – Alene M.

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